Fig. 3

Correlation matrix with Spearman’s correlation coefficients for all variables. As some of the variables are not independent of the diagnosis (healthy, mild EA, moderate EA, severe EA), the correlations must be interpreted accordingly. The cough score, as part of the clinical score, showed the strongest correlation with diagnosis, highlighting the importance of medical history in equine asthma. (Abbr.: EA = equine asthma, BALF = bronchoalveolar lavage fluid, PaO₂ = arterial oxygen partial pressure, AaDO₂ = Alveolar-arterial oxygen gradient, PaCO₂ = arterial carbon dioxide partial pressure)